A lovely bit of fun in which the two teams meet in a library, and there is world-threatening danger and the Doctor and Daniel bonding over bow ties, books and the promise of a visit to yet another library.

The Doctor was said to be at Dallas in 1963. So were quite a number of other time travellers, including a certain gang who were only in search of a decent curry. This is brilliant, from the Hitch-Hiker-esque intro on time travel, the nods to other time travellers who were also hanging around, the Doctor’s reaction to the Dwarfers’ current plan and the ending. Another example of a fanfic author making excellent use of a throwaway line from an episode.

This isn’t strictly a crossover. In fact, being set at in specific space and time, maybe it should be historical. But the Doctor investigates fixed voting at the Eurovision Song Contest (while approving of Terry Wogan’s commentary) feels like a crossover to me. And it’s marvellous fun.